/*******************************************************************************
 * Copyright 2010 DemandSpot
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package com.demandspot.client.table;

import java.util.Comparator;

public class ColumnComparator<RowModel, CellValue extends Comparable<CellValue>> implements Comparator<RowModel> {
	private int direction = 1;
	private CellRenderer<RowModel, CellValue> cellRenerer;
	
	ColumnComparator(CellRenderer<RowModel, CellValue> cellRenerer) {
		this.cellRenerer = cellRenerer;
	}
	
	final void setAscending(boolean ascending) {
		this.direction = ascending? 1 : -1;
	}
	
	public final int compare(RowModel r1, RowModel r2) {
		CellValue c1 = cellRenerer.getCompareValue(r1);
		CellValue c2 = cellRenerer.getCompareValue(r2);
		return c1.compareTo(c2) * direction;
	}
}
